The present invention relates, in general, to musical instruments of novel design and construction, and more particularly to a new and improved instrument such as a guitar, banjo, mandolin, or the like.
Guitars and other stringed instruments of the ampliphonic or resophonic type, wherein the instrument's bridge is mounted on a shaped diaphragm located within the body of the instrument whereby the bridge causes the diaphragm to vibrate to provide increased amplitude, are well known and are disclosed, for example, in Pat. Nos. 2,045,265 and 3,435,721 issued to the inventor herein. As pointed out in those patents, the resonant diaphragm for such instruments generally is mounted within the instrument body on a supporting tone chamber which is secured to the housing, with the shape, size and material of the diaphragm and its mounting, the construction of the bridge assembly on which the strings rest, and the connection between the bridge and the diaphragm being critical factors in producing the proper and desired tone. The sound producing diaphragm in such instruments normally is protected by a cover secured to the top thereof, over which pass the strings and through which extends the bridge. The motion of the strings when the instrument is played is transmitted through the bridge to the diaphragm, which then vibrates to produce the desired tone.
Because of the criticality of the arrangement of parts in an ampliphonic instrument, it has been a difficult task to construct such an instrument and to secure the various parts in a relationship which insures that the desired tone can be produced in each instrument and maintained over a period of time. The mounting of the diaphragm in the instrument body has been accomplished in a number of ways in the past, but a delicate balance must be maintained between securing the diaphragm sufficiently to insure that it will not move, while yet permitting it to vibrate to produce the desired tone. Further, adjustment of string tension, and thus the pressure on the bridge, to insure maximum transfer of vibratory motion to the diaphragm has been a delicate task since tightening and loosening of the strings to tune the instrument varies the pressure on the bridge and changes this relationship. Thus, tuning of the instrument while retaining the desired sound has been difficult. The mounting of the bridge assembly on the diaphragm has also presented problems in that a firm contact must be maintained between the bridge and the diaphragm without dampening the vibrations transferred to the diaphragm, so that a clear sound is obtained.